Note: Descriptions are shown in the official language in which they were submitted.
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8 "METHOD AND APPARATOS FOR HEAT
SFALING IJ~1BELS ON CONTAINERS"
11
12 This imrention relates to apparatus for and a
13 method of applying film, labels and the like to articles
14 such as cylindrical containers in which the film, label or
the like (hereinafter referred to as ~label") is applied to
16 such an article (hereinafter referred to as a "container")
17 wrapping the label around the container, lapping the
18 trailing end of the label over the leading end and securing
the leading and trailing ends together by heat and
2o pressure.
21
22 FIELD OF TH . TNVF'NTTL~N
23
24 It is common practice to apply labels to
28 cylindrical containers by adhering the leading end of the
26 label to the body of the container, as by means of
27 adhesive, wrapping the label around the container, lapping
28 the trailing end of the label over the leading end and
29 securing the trailing end to the leading end by means of an
30 adhesive.
31
32 BACKGROUND OF THE I .taTTnrr
33
34 The adhesive may be a hot melt glue or other
35 separately prepared adhesive or it may be an adhesive
36 tornaed in situ on the label by application of a solvent
37 Which is absorbed into the material of the label and forms
38 a sticky adhesive substance which secures the label.
39 Subsequently the solvent is evaporated.
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1 SUMMA.R V
OF THF T~NTION
2
Where a hot melt glue (that is a glue which is
4 melted by heat) is used, it may be applied to the container
to adhere the leading end of the label to the container and
hot melt glue is applied to the trailing end of the label.
7 An example of such practice is described in U.S. Patent No.
8 4,108,710. Alternatively the hot melt glue may be applied
directly to both the leading and trailing ends of the label
as in U.S. patent No. 4,181,555.
11
12 Glue applied in this manner has certain
13 disadvantages. For example, if containers so labelled are
14 stored or shipped in very cold weather the glue may
crystallize and fail.
16
17 A disadvantage of the solvent seal method is that
18 it requires equipment to evaporate the solvent and dispose
19 of it without contaminating the environment.
21 Another method of applying labels to containers
22 which avoids the use of~hot melt glue and of a solvent is n
23 method in which label material is wrapped around n spinning
24 mandrel, n label length is severed and the trailing end of
the label is lapped over the lending end. Heat and
26 pressure are applied to weld the trailing and leading ends
27 together. The resulting preformed tube is removed from the
28 mandrel and it is then placed over a container and shrunk
29 onto it. This method supers certain disadvantages. For
example, it requires two machines, namely a machine to pre-
31 torm the tubes and another machine to apply the tubes to
32 and shrink them onto containers. Also it is wasteful of
33 material inasmuch as the label material must be made
34 oversize so that the pretormed tubes can !it over the
containers.
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37
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1 In another method, described in U.S. patent No.
2 4,724,029, heat is applied by a blower to the trailing end
3 of the label to soften it so that it will weld to the
4 leading end. The heat is applied by a fixed blower which
is external to the vacuum drum which carries the labels.
6 Such method has disadvantages. For example the blower must
7 be timed to apply heat to the proper area of the label.
8 the difficulty of such timing increases with the speed of .
9 the machine. Also the time available for application of
hot air is inversely proportional to the machine speed,
11 which sets an upper limit on the speed of the machine.
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13 It is an object of the present invention to
14 provide a method of and apparatus for applying labels to
containers which avoid or substantially diminish the
16 aforesaid disadvantages.
17
18 It will be understood that the material applied
19 need not be labels but may be, for example, protective
and/or decorative covers and that the articles need not be
21 containers. For convenience and brevity "labels" and
22 "containers" will be referred to herein and the invention
23 will be described with reference thereto.
24
In accordance with the invention a label material
26 is employed which can be softened by heat and when softened
27 and subjected to pressure will create a weld as, for
28 example, at the overlap between the leading and trailing
29 ends of the label. The label is applied in such manner to
a container, that is with the trailing and lapping over the
31 leading end, and pressure is applied to weld the heat
32 softened trailing end to the leading end and complete the
33 labeling operation on the container itself. Examples of
34 suitable label material !or this purpose are polyethylene .
and polypropylene label material, also polystyrene. The
36 label material is preferably either non-heat shrinking or
37 if heat shrinkable, it is preferably a material which does
38 not shrink rapidly.
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The leading end of the label may be adhered to the
container by heating it to soften it provided the container is
made of appropriate material, e.g. glass containers (empty or
full) or filled plastic containers. However, it is preferred
to attach the leading end of the label to the container by an
adhesive, e.g. by application of a solvent to the label or by
application of a hot melt glue to the container or to the
leading end of the label. The attachment of the leading end of
the label to the container, e.g. by spots of hot melt glue
applied to the leading end, such tacking being sufficient to
hold the label on the container until it is fully wrapped and
the heat softened trailing end is secured to the leading end.
The invention may be summarized according to one
aspect as a machine for applying labels or the like to
cylindrical containers or the like, such labels being of heat
softenable material and each having a leading end and a
trailing end, said machine comprising: (a) a cylindrical vacuum
drum mounted for rotation about its cylinder axis and adapted
to receive labels in succession on its cylinder surface at a
label receiving station, to hold each label on such surface and
to transport each label to a label applying station, said drum
having an opening in its cylinder surface adjacent and behind
the trailing end of a label when placed on such surface; (b)
means for applying labels in succession to the cylinder surface
of the drum as it rotates with the leading end of each label
remote from, and the trailing end of the label close to said
opening (c) means for transporting said containers through a
path which is tangent to a label on the drum at the label
applying station and for rotating each container to wrap a
label around the container and to lap the trailing end of the
label over the leading end and to apply pressure while so doing
(d) and heat applying means for applying heat to the trailing
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end of each label while it is on the cylinder surface of the
drum and while the label is being transported to the label
applying station and is being applied to a container, such heat
serving to soften the trailing end of the label to enable it to
be welded to the leading end by pressure, said heat applying
means comprising: (1) a heat applicator located within the drum
and rotating therewith, said applicator having a head portion
which can be extended outwardly through said opening for
application of heat to the trailing end of a label on the drum
and which can be withdrawn from its extended position for
clearance purposes, (2) means for operating said applicator to
move it to its extended position and to hold it in such
position during a large portion of the travel of a label
between the label receiving and label applying stations, and to
move the applicator to its withdrawn position when it
approaches and passes the label applying station and (3) means
to apply heat from said head to the trailing end of each label
during such large portion of its travel.
According to another aspect the invention provides in
the method of applying labels to containers wherein labels are
supplied in succession at a label receiving station to the
cylinder surface of a cylindrical vacuum drum rotating about
its cylinder axis, each label so applied having a leading end
which is first contacted with the vacuum drum and having a
trailing end, and wherein each label so applied to the vacuum
drum is transported by the vacuum drum to a label applying
station and is released at the label applying station, and
wherein containers are transported in succession to a position
of tangency to the vacuum drum at the label applying station
and wherein each container is rotated to wrap an applied label
about itself with the trailing end of the label overlapping the
leading end, the improvement which comprises applying heat to
the trailing end of the label for substantially the entire path
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of the trailing end of the label from the label receiving
station to the label applying station, such heat being
sufficient to soften the trailing end of the label to allow it
to be welded to the leading end of the label, and applying
pressure to the overlapped trailing end to so weld it to the
leading end.
BRIEF DESCRIPTION OF THE DRAWINGS
Certain embodiments of the invention are shown by way
of example in the accompanying drawings, in which:
Figure 1 is a diagrammatic view of that portion of a
labeling machine to which the present invention is applicable;
Figure 2 is a diagrammatic cross sectional view of a
vacuum drum such as that shown in Figure 1 showing the cam and
nozzle construction employed to apply heat to the trailing end
of a label;
Figure 3 is a vertical section taken through a vacuum
drum such as that shown in Figure 2 showing the cam and nozzle
construction in more detail and also the hot air supply;
Figure 4 is a section taken along the line 4 - 4 of
Figure 3;
Figure 5 is a section taken along the line 5 - 5 of
Figure 3;
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1 Figure 6 is a plan view of the cam used to
2 operate the hot air nozzle or nozzles: and
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4 Figure 7 is a plan view of the cam follower.
6 DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
7
8 Referring now to Figure 1, a labeling machine is
9 shown at 10 comprising a vacuum drum 11, a turret 12 such
as described in U.S. Patent 4,108,709, a label strip 13 and
11 a glue applicator 14. The strip 13 is a continuous strip
12 coming from a roll by Way of suitable feed mechanism (not
13 shown), individual labels being severed by a cutter 15.
14 Suitable feed mechanisms and suitable cutters are wall
known in the art, being shown, for example, in U.S. Patent
16 No. 4,108,710. Alternatively, precut labels may be
17 supplied from a stack and extracted and supplied to the
18 vacuum drum by means well known in the art. The vacuum
19 drum may be provided with ridges on its cylindrical surface
to elevate the leading and/or trailing ends of the label,
21 e.g. to contact the leading end with a glue applicator 14
22 to apply a strip or spots of hot melt glue to the leading
23 end of each label whereby it is secured to a container.
24 The turret 12 is supplied with containers entering at 16:
each container in turn is brought into tangent contact with
26 the leading end of a label which is adhered thereto: the
27 container with a label so attached is spun to wrap the
28 label around it: a»d the trailing end is lapped over the
29 leading end and ie secured thereto. Labeled containers are
released by the turret 12 and leave at 17.
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32 Alternatively, a straight through labeling
33 machine such as that clescribsd in Mitchell U.S. Patent
34 Application Serial No. 200,359, tiled May 31, 2988,
entitled "STRAIGHT THROUGH LABELING MACHINE" may be used.
36 In such machine containers proceed in a straight line and
37 during transit they are brought into tangent contact with
38 labels on the vacuum drum and are spun after such contact.
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Yet another method is that described in U.S.
Patent No. 4,500,386 in which each container, after being
brought into contact with the leading end of a label on a
vacuum drum, is confined, together with its label, between
the cylindrical surface of the vacuum drum and a roll-on
pad concentric to the vacuum drum and is caused to spin
thereby wrapping the label around it.
Heretofore in machines of these types, the
trailing end of the label has solvent or a hot melt glue
applied to it to adhere to the leading end of the label to
the trailing end. In accordance with the present invention
heat is applied to the trailing end to soften it and cause
it to weld with and adhere to the leading end.
Referring now to Figure 2, the vacuum drum 11 is
shown together with a glue applicator 14 and as having a
label 20 on its cylindrical surface. The vacuum drum has
one or more (shown as two) openings 21 in the periphery for
access of a nozzle 22 pivoted on a stationary shaft 23
which is mounted on the drum 11. The nozzle 22 has a
forward portion 24 terminating in a head 25, the portion 24
and head 25 being formed with a passageway and a slit
respectively, (neither of which is shown) for passage of
hot air to heat the trailing end 20a of label 20. The
nozzle 22 has a rearward extension 26 which carries a cam
follower roller 27 which rides on the surface of a
stationary cam 28. The cam 28 has a low dwell 30, a high
dwell 31 and a corresponding rise portion 32 and descending
3o portion 33. The cam 28 may be a face cam with a track that
confines the cam follower roller 27 or it may be a plate
cam and the nozzle 22 may be biased by a spring (not shown)
to keep the roller 27 in contact with the cam.
The cam 28 is designed so that the nozzle 22 is
extended as shown at the top in Figure 2 so as to apply hot
air through tip 25 from a time just after the trailing end
20a is placed in the position shown fn Figure 2 until the
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1 trailing end ie about to leave the vacuum drum. If the
2 glue applicator 24 is of the type which is retracted from
3 the vacuum drum after it has applied glue to the trailing
4 end of the label, such as described in U.S. Patent
4,108,710 at Column 7, lines 25 to 32, this mode of
6 operation is feasible. Alternatively, the glue may be
7 applied in a non-contact manner, e.g. by a remote nozzle
8 and propelled toward the label. If the glue applicator is
9 held at all times in the same position and physically
contacts the trailing end of the label and it is necessary
11 to clear any obstruction such as the tip 25 of nozzle 22,
12 the cam 28 may be provided with a second rise portion to
13 accomplish this as shown in Figure 6 below.
14
Alternatively, glue may be applied to the
16 container as, for example, in U.S. Patent 4,108,710 in
17 which event the glue applicator 14 may be eliminated.
18
19 Hot air may be supplied to the nozzle 22 at the
time desired by any suitable means while the trailing end
21 is on the vacuum drum, for example by the means shown in
22 Figures 3 and 4 described below.
23
24 It will be apparent that by this means hot air is
applied to the trailing end 20a of the label 20 during most
26 of the time it is on the vacuum drum and will act to soften
27 the trailing end of the label. Therefore, when the
28 softened trailing end of the label is pressed against the
29 leading end, e.g. by means of a pad 48 shown in the Figure
of U.S. Patent 4,500,386, the leading and trailing ends of
31 the label will be welded together. Other well known means
32 !or applying pressure to the overlapping leading and
33 trailing ends of the label may be employed.
34
Instead of hot air, radiant heat from an
36 electrical heater in the tip of the nozzle may be employed,
37 which is activated in time with the cam 28.
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1 Referring now to Figures 3 and 4, a vacuum drum
11 is shown mounted on and for rotation with a shaft 40
which is rotatably mounted in the frame 41 of a labeling
machine. A nozzle 42 is provided to perform the function
described above of the nozzle 22 and a cam 43 is provided
to perform the function described above of the cam 28.
A hot air inlet 44 is formed in a stationary part
45 of the machine, such hot air inlet communicating with a
source (not shown) of hot air at suitable temperature and
pressure, e.g. 1200'F and 80 psi gauge. The temperature
and pressure, particularly the temperature, will vary with
the speed of the machine. If the label material is heat
shrink material and it is intended to shrink it as in U.S.
Patent No. 4,704,173, the time of exposure of the label
material to hot air should be sufficient to soften it but
insufficient to shrink it. The hot air inlet communicates
with a plenum chamber 46 formed in a plenum block 47. Such
plenum chamber is described in more detail below with
reference to Figure 4. The plenum block is stationary but
can be adjusted angularly by a rod 48. The~plenum forms an
arc of a circle and communicates with a tube 49 which
carries at its upper end the nozzle 42. The lower end of
the tube 49 rests on a sealing plate 55 which is formed
with an opening 56 and the plate 55 in turn rests on a wear
plate 57 made of Micarta*or other suitable material which
is in contact with the upper edge of the plenum. An
expansion spring 58 confined between a shoulder 59 on the
tube and the plate 55 maintains an air tight seal but
allows rotation of the tube with the vacuum drum 11 about
the letter's axis and also rotation about its own axis.
The cam 43 is supported on a cam support 60 but
can be rotated for adjustment by a rod 61 (see Figure 4)
and it has a profile as shown in Figure 6 including a high
dwell 52, a decline 63, a low dwell 64, a rise 65, a short
dwell 66, a decline 67, a second low dwell 68 and a rise
69.
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1 A cam follower roller 70 is rotatably mounted on
2 a bracket 71 which is keyed at 72 (see Figure 7) to
the
3 tube 49. A torsion spring 73 is fixed at one end to
a pin
4 74 fixed to the vacuum drum 11 and at its other end
it is
fixed to the cam bracket 71. This spring holds the cam
6 follower 70 against the cam 43.
7
8 The nozzle 42 is fixed to the upper end of the
9 tube 49: it flares out at 42A to at least the width
of a
label and it is shaped to pass through the opening 21
in
11 the vacuum drum. It will be apparent that as the vacuum
12 drum and with it the tube 49 and the nozzle 42 rotate
about
13 the axis of the shaft 40, the nozzle will be held retracted
14 while the cam follower is in contact with the high dwell
62; it will then be extended to deliver hot air while
the
16 cam follower is in contact with the low dwell 64; it
will
17 again be retracted momentarily while the follower is
in
18 contact with the high dwell 66 and will be extended
again
19 while the cam follower is in contact with the low dwell
68.
The purpose of the high dwell 66 is to retract the nozzle
21 42 momentarily to clear the glue applicator which applies
22 glue (or solvent) to the leading end of a label. If
glue
23 is applied to the container instead of to the label,
such
24 clearance will be unnecessary and the high dwell 66
may be
eliminated.
26
27 Referring now to Figure 4, the plenum chamber 46
28 extends for about ~~ between end closures 75 and 76.
29 The effective space is cantrolled by a~ tapered plug
77
which may bs moved to any desired position. A second
31 moveable plug 78 is provided which has at its lower
portion
32 a passage 79 which permits hot air to llow.into the
space
33 46A above and to the left of the plug 78 as viewed in
34 Figure 4. This plug is located in a position such that,
as
the nozzle 42 passes the; glue wheel and is r~tracted,
the
36 hot air supply (which is still operating) will not issue
37 from the nozzle 42, 42a and blow the trailing end of
the
38 label off of the vacuum drum. The function of the passage
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1 is to allow hot air to continue its passage into the space
2 46A of the plenum.
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4 It will therefore be apparent that a novel and
useful labeling machine has been provided.
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